Refrigeration



April 16, 1957 J. E; KRUG 2,788,645

REFRIGERATION Filed Dec. 29, 1954 I 2 Sheets-Sheet 1 INVENTOR. BY v 49 41;

Jed arm/6W9 J. E. KRUG REFRIGERATION April 16, 1957 2 Sheets-Sheet 2 Filed Dec. 29, 1954 INVENTOR. BY (5: M?

452;, armfi/iy ZZQJ Unite REFRIGERATION John E. Krug, Evansville, Ind., assignor to Servel, Inc., New York, N. Y., a corporation of Delaware The present invention relates to refrigeration and more particularly to purging hydrogen from refrigeration apparatus.

While the present invention may have other applications, it is particularly adapted for apparatus used in vacuum type absorption refrigeration systems. Such systems using water as a refrigerant and a salt solution for an absorbent have been used extensively for air conditioning. Hydrogen is apt to occur in the apparatus which probably results from corrosion and, due to the low pressure in the apparatus, a small quantity of non-condensable hydrogen blankets a large area of heat transfer surface with an insulating layer. It has heretofore been the practice to continuously transfer hydrogen from the active part of the apparatus to a storage vessel having a palladium wall through which the hydrogen diffuses to the ambient atmosphere. However, if the palladium wall is contacted by absorbent, as may occur from tipping or tilting the apparatus during transit, the palladium wall becomes contaminated or poisoned which prevents the diffusion of hydrogen therethrough.

One of the objects of the present invention is to provide a construction and arrangement of elements in a closed refrigeration apparatus for preventing liquid therein from flowing into contact with the palladium wall in a gas storage chamber when the apparatus is tilted or tipped to any position.

Another object is to provide an apparatus of the type indicated with a conduit inclined upwardly throughout its length from an active part of the apparatus to a gas storage vessel and so constructed as to project above the static level of solution at any tilted position of the apparatus.

Another object is to provide an apparatus of the type indicated in which the palladium wall communicates with the storage vessel at its center and the vessel is constructed to provide sufficient capacity to receive any liquid in the connecting conduit at a level below its center.

Still another object is to provide an apparatus of the type indicated which is of simple and compact construction, economical to manufacture and reliable in performing its intended function.

These and other objects will become more apparent from the following description and drawings in which like reference characters denote like parts throughout the several views. It is to be expressely understood, however, that the drawings are for the purpose of illustration only and not a definition of the limits of the invention, reference being had for this purpose to the appended claims. In the drawings:

Fig. 1 is a diagrammatic view of a vacuum type absorption refrigerating apparatus incorporating the novel fea tures of the present invention and showing the upwardly directed conduit projecting laterally beyond the liquid containing elements in two directions;

Fig. 2 is an end elevational view showing the upwardly directed conduit projecting laterally beyond the liquid containing elements in two other directions;

States Patent Fig. 3 is an enlarged view of the gas storage vessel showing a pipe having one end open at the center thereof and its opposite end connected to a cell containing the palladium wall;

Fig. 4 is a further enlarged sectional view of the palladium cell illustrated in Fig. 3 and showing the palladium wall in the form of a generally upright tube extending through a chamber with a heating element surrounding the chamber;

Fig. 5 is a front elevational view of the apparatus tipped to the left from the position illustrated in Fig. l and showing one section of the connecting conduit projecting upwardly above the static level of liquid therein;

Fig. 6 is a View similar to Fig. 5 showing the apparatus tipped to the right from the position illustrated in Fig. l and showing another section of the connecting conduit projecting above the static level of solution in the apparatus;

Fig. 7 is an end view of the apparatus tipped to the left from the position illustrated in Fig. 2 and showing another section of the conduit projecting above the static liquid level therein;

Fig. 8 is a view similar to Fig. 7 showing the unit tipped to the right from the position illustrated in Fig. 2 and showing still another section of the conduit projecting above the static liquid level therein;

Fig. 9 is a view illustrating the apparatus up-ended from the position shown in Fig. 1; and

Fig. 10 is an end view showing the apparatus up-ended from the position illustrated in Fig. 2.

Referring to the drawings, the invention is shown applied to a vacuum type absorption refrigeration unit generally similar to that illustrated and described in an application for United States Letters Patent of E. M. Stubblefield, Serial No. 265,418, filed January 8,. 1952. Suflice it to state herein that the refrigeration apparatus comprises a generator 11, a condenser 12, an evaporator 13, an absorber 14, and a combined liquid heat exchanger and leveling vessel 15 all contained and supported in an angle iron frame 16. The elements are interconnected to provide a closed system that is initially evacuated and charged with a water solution or lithium bromide or other suitable refrigerant and absorbent combination.

The generator 11 comprises a shell 17 forming a heating chamber 18 enclosing upright tubes 19. The generator tubes 19 extend between a lower inlet chamber, not shown, and an upper separating chamber 29. Steam supplied to the heating chamber 18 at atmospheric pressure expels refrigerant vapor, water, from the lithium bromide solution in the upright tubes 18 and the expelled vapor is utilized to raise the solution into the separating chamber 26 for gravity fiow through the solution circuit as later explained.

Refrigerant vapor flows from separating chamber 20 through a vapor pipe 21 to the condenser 12 where it is condensed to a liquid. The condenser may be of any suitable type such as a surface type having a shell and tubes through which cooling water flows. Liquid refrigerant flows from the condenser 12 to the evaporator 13 through an orifice device 22 and conduit 23. The orifice device 22 is like that described and claimed in United States Letters Patent of N. E. Berry 2,563,575, issued August 7, 1951, which permits the flow of liquid and non-condensible gases from the condenser 12 to the evaporator 13 while maintaining a difference in pressure therebetween.

The evaporator 13 comprises horizontally arranged finned tubes 24 extending between headers 25 and 26. The tubes 24 project into the headers 25 and 26 and alternate tubes have cups 27 at opposite ends which underlie the ends of the next uppermost tube so that refrig 0 erant flows through successive tubes from the top to the bottom of the evaporator. Evaporator 13 .is mounted on 3 the absorber 14 with the headers 25 and 26 opening into the top of the absorber.

Absorber 14 comprises a generally cylindrical shell having a plurality of tubes 3-!) with alternate adjacent ends connected together in vertical rows to provide serpentine coils. The lower ends of the plurality of serpentine coils are connected together by a header 31 which, in turn, is connected to a cooling water inlet conduit 32. The upper ends of the vertical coils are connected together by a header 33 and the header is connected by a conduit 3 to one end of the condenser 12 for delivering cooling water for flow through the tubes thereof. A conduit 35 is provided at the other end of the condenser from which cooling water can flow to waste or a cooling tower if one is used. Thus, cooling water flows successively through the coils 3%) of the absorber 14 and tubes of the condenser 12. Overlying the coils 30 in the absorber 14 is a liquid distributor 36 for distributing liquid onto the uppermost tube of each coil from which it drips onto the next lowermost tube from the top to the bottom of the absorber.

The absorption solution circuit comprises a path of flow for solution weak in refrigerant from the generator 11 to the absorber 14 and a path of flow for solution strong in refrigerant from the absorber to the generator. The path of flow for solution weak in refrigerant comprises a conduit 37 depending from the separating chamber 26 and connected to the inner passage between the plates 38 of the combined heat exchanger and leveling vessel 1.5 and a conduit 39 connecting inner passage of the heat exchanger to the liquid distributor 36 overlying the coils 341 in absorber 14. The path of flow for solution strong in refrigerant comprises a conduit 40 depending from the absorber shell 14 and connected to the easing 41 surrounding the plates 38 of the heat exchanger and constituting the outer path of flow. A conduit 42 connects the casing 41 to the base of the generator .11 to complete the solution circuit. The construction of the combined heat exchanger and leveling vessel 15 is like that descnibed and claimed in United States Letters Patent to Walter M. Simpson No. 2,685,781, issued August 10, 1954. Thus, solution lifted in the generator tubes 19 to the separating chamber 20 flows by gravity through the absorber i4 and combined heat exchanger and leveling'chamber 15 back to the base of the generator to complete a cycle.

Absorption solution flowing over the relatively cold coils 30 in the absorber 1 absorbs refrigerant vapor and causes the refrigerant to evaporate in the tubes 24 of the evaporator 13 at a low pressure and temperature to cool air flowing over the exterior of the tubes. The difference in pressure between the condenser 12 and evaporator 13 is maintained by the orifice device 22 and the difference in pressure between the absorber 14 and generator 11 is maintained by pressure balancing columns of solution in the conduits 39 and 4'1 For example, during operation solution will stand at some level X in conduit 37 to maintain a pressure balancing liquid column in conduit 39 connected thereto through the inner passage 38 of the liquid heat exchanger 15, and levels Y and Z in conduit 40 and casing 41 of the heat exchanger, respectively, to maintain a pressure balancing column therebetween.

A purging device 44- like that described and claimed in United States Letters Patent to C. A. Roswell Re. 23,093, issued March 22, 1949, is provided for continuously withdrawing non-condensable gases such as hydrogen from the active part of the system and transferring the gases to a gas storage vessel 45. The purging device 44 comprises an auxiliary absorber 46 having a cooling coil therein, not shown, connected between the cooling water inlet 32 and outlet conduit 34 to and from the absorber coils 30, respectively. Absorption solution weak in refrigerant flows from conduit 39 through a branch 47 having a metering orifice 48 into the auxiliary absorber 46 for flow over the cooling coil. A suction tube 49 extends from the bottom and center of the absorber vessel 14 to the side of the auxiliary absorber 46 and a fall tube 50 depends from the auxiliary absorber to a separating chamber 51 at the base of the apparatus. Conduit 41 depending from the absorber 14 to the liquid heat exchanger 15 is connected to the separating chamber 51 adjacent the bottom thereof and a conduit 52, later to be described in detail, projects upwardly from the side of the separating chamber51 to the gas storage vessel 45. A palladium cell 53, see Fig. 2, is provided for diifusing hydrogen from the storage vessel to the ambient atmosphere. As thus far described the apparatus is substantially identical with that illustrated and described in the Stubblefield application referred to above.

In accordance with the present invention, a construction and arrangement of elements is provided for preventing absorption solution from contacting the palladium wall in the gas diffusion cell if the apparatus is tipped or tilted to any position as may occur during transit. To this end the conduit 52 connecting the separating chamber 51 to the gas storage vessel 45 is inclined upwardly throughout its length in the operating position of the apparatus illustrated in Fig. l but has sections projecting above the static liquid level in the apparatus in any tilted position. Referring to Fig. 1, the lower section of the conduit 52 projects laterally to a point 52a beyond any liquid containing element. An intermediate section of conduit 52 projects laterally to the right to a point 52b beyond any liquid containing element. The intermediate section of conduit 52 is in the form of a hairpin shaped bend with each leg of the hairpin inclined upwardly so as to permit gas to flow upwardly and liquid to flow downwardly. Referring to Fig. 2 the lower section of conduit 52 projects to the right to a point 52c above any liquid containing element in a plane at right angles to the plane illustrated in Fig. 1. The intermediate section of conduit 52 also projects across the unit to the left to a point 52d beyond any liquid containing element in the same plane. An upper section of conduit 52 connects the intermediate section to the gas storage vessel 45.

In addition to the construction of the conduit 52 the gas diffusion cell 53 containing the palladium wall communicates with the interior of the gas storage vessel through a pipe 54 having an open end 54a located at the center of the gas storage vessel 45. The gas diffusion cell 53 comprises a closed cylindrical chamber 55 at the opposite or outer end 5412 of the pipe 54, see Figs. 3 and 4, and the palladium wall is in the form of a tube 56 extending in a generally vertical direction through the cylindrical chamber at its axis. Surrounding the chamber 55 is a heating coil 57 which is energized during operation of the system. Ga storage vessel 45 is so constructed as to have sufiicient capacity below the open end 5401 of pipe 54 to receive the maximum amount of solution in conduit 52 when the apparatus is tilted to any position. One embodiment of the invention having now been described in detail, its mode of operation is explained as follows.

When the apparatus is in the upright position illustrated in Fig. 1 it is ready to be shipped to the place where it is to be used or to be operated at such place. In this upright position of the unit the liquid level therein is below the top of the combined heat exchanger and leveling vessel 15 at some level such as Z as shown in Fig. 1. During shipment the unit may be tilted or tipped to any of the positions illustrated in Figs. 6 to 10 without any of the solution contacting the palladium wall 56 in the hydrogen diffusion cell 53.

If the refrigeration unit is tipped to the left from the position illustrated in Fig. 1 to that illustrated in Fig. 5, the point 52b of the intermediate section of the upwardly inclined conduit :52 is located above the liquid level in the tilted position of the apparatus and thereby'prevents flow of solution to the gas storage vessel 45. If theunit is tipped to the right from the position illustrated in Fig. 1 to that illustrated in Fig. 6, the point 52a of the upwardly inclined conduit 52 projects above the liquid level in the unit and prevents the flow of solution to the gas storage chamber 45. If the unit is tipped from the position illustrated in Fig. 2 to the position illustrated in Fig. 7, the point 520 between the lower and intermediate sections of the upwardly inclined conduit 52 projects upwardly above the liquid level in the unit to prevent the flow of solution to the storage chamber 45. If the unit is tipped to the right from the position illustrated in Fig. 2 to that illustrated in Fig. 8, the point 52d of the upwardly inclined conduit 52 projects above the solution level in the unit to prevent it from flowing into the gas storage vessel 45. If the unit is then tilted back from any of the four positions illustrated in Figs. 6 to 8 to the original position illustrated in Fig. 2, the solution merely flows downwardly through the inclined sections of the conduit 52 back to the level Z Without any solution entering the gas storage chamber 45.

However, if the unit is further tipped from the positions illustrated in Figs. 5 and 6 to the up-ended position illustrated in Fig. 9, a small amount of solution in the lower and intermediate bight portion of the conduit 52 may flow into the gas storage chamber 45. However, solution will run from the separating chamber 51 into other elements before it can flow through conduit 52 into the gas storage vessel 45. Gas storage vessel 45 has suffioient capacity relative to the amount of solution contained in the conduit 52 so that the solution entering the vessel will not rise to the level of the open end 54a of the pipe 54 at the center thereof. Thus, solution is prevented from entering the pipe .54 and flowing into the cell 53 andthereby prevented from contacting the palladium wall 56 in the .cell. If the unit is tipped from the positions illustrated in Figs. 7 and 8 to the position illustrated in Fig. 10, only the small quantity of solution in the lower and intermediate sect-ions of the conduit 52 will flow into the gas storage chamber 45 which, as stated above, has sufiicient capacity to receive the solution below the level of the open end 54a of the pipe 54 connected to the cell 53. If the unit is continually turned either on its side or end through a complete revolution, the small amount of solution in the gas storage chamber 45 will flow down the inclined sections of conduit 52 to the initial level Z. Thus, the palladium wall 56 of the gas diifusion .cell 53 is prevented from being contaminated from contact by absorption solution during transit.

To operate the unit in the upright position illustrated in Fig. 1 at the place where it is to be used, heat in the form of steam at atmospheric pressure is supplied to the chamber 18 surrounding the upright tubes 19 of the generator. Heat from the steam is transmitted through the walls of the tubes 19 to the solution therein and expels refrigerant vapor therefrom. The refrigerant vapor acts to lift the solution into the separating chamber 20, as previously explained, and the vapor iiows to the condenser 12 where it is liquefied. Liquid refrigerant then flows by gravity through the orifice device 22 and conduit 23 into evaporator 13 and through successive tubes 24 from the top to the bottom thereof.

Simultaneously, solution weak in refrigerant flows from the separating chamber 20 through the conduit 37, inner passage 38 of the liquid heat exchanger and conduit 39 to the absorber 14 where it flows over the surface of the tube 30 therein. Absorption of refrigerant vapor in absorption solution reduces the vapor pressure of the refrigerant in the evaporator 13 and causes it to evaporate at a relatively low temperature to produce a refrigerating effect. The solution strong in refrigerant then flows from the bottom of the absorber 14 back to the base of the generator 11 in a path of flow comprising the depending conduit 40, outer passage of the liquid heat exchanger 15 and conduit 42 to complete the cycle of operation.

Any hydrogen or other non-condensable gases occur ring in the closed apparatus is swept by the flowing vapor in the high pressure side of the system to the outlet from the condenser 12 where it passes through the orifice device 22 into evaporator 13 and the gases in the low pressure side of the system are swept by the flowing vapor to the bottom and center of the absorber 14 where there is a minimum turbulence. Auxiliary absorber 46 operates at a lower pressure than the pressure in the main absorber 14 and causes the non-condensable gases, principally hydrogen, to be drawn thereto through the suction pipe 49. The gases are transferred from auxiliary absorber 46 to separating chamber 51 through the drop tube pump 50. Liquid flows from the separating chamber 51 through the conduit 49 into the outer passage of the liquid heat exchanger 15. The non-condensable gases collect in the top of the separating chamber 51 until the liquid level is depressed below the lower end of the upwardly inclined conduit 52. The non-condensable gases then escape into the conduit 52 and flow upwardly therethrough into the gas storage vessel 45. It will be noted that all sections of the conduit 52 are inclined upwardly so that gas will flow unimpeded to the gas storage vessel 45.

During operation of the unit the heating element 57 is energized to heat the cell 53 including the palladium tube 56 therein. Hydrogen gas in the chamber 55 diffuses through the wall of the palladium tube 56 due to the higher partial pressure of hydrogen in the chamber than in the ambient. Due to the generally vertical arrangement of the palladium tube 56 a thermo-siphon action is produced causing ambient air to flow through the center of the palladium tube and sweep hydrogen gas therefrom as fast as it diffuses therethrough. As hydrogen diffuses from chamber 55 of cell 53 through the palladium wall 56 it is replaced by additional hydrogen from storage vessel 45 It will now be observed that the present invention provides a construction and arrangement of elements for purging hydrogen from refrigeration apparatus through a palladium wall and for preventing liquid from flowing into contact therewith when the apparatus is tilted or tipped to any position. It will also be observed that the present invention provides an apparatus of the type indicated with a conduit connecting the active parts of the apparatus to a gas storage vessel and in which the conduit is inclined upwardly throughout its length and constructed to project above the solution level at any tilted position of the apparatus. It will also be observed that the present invention provides a palladium wall which communicates with the center of a gas storage vessel having sufiicient capacity to receive any solution flowing thereto below the center of the vessel. It will still further be observed that the present invention provides an apparatus of the type indicated which is of simple and compact construction, economical to manufacture and reliable in performing its intended function.

While a single embodiment of the invention is herein illustrated and described, it will be understood that modifications may be made in the construction and arrangement of elements without departing from the spirit or scope of the invention. Therefore, without limitation in this respect, the invention is defined by the following claims.

I claim:

1. In a vacuum type absorption refrigeration apparatus containing absorption solution adapted to be circulated therein and in which hydrogen is apt to occur, a gas storage vessel, means for transferring hydrogen from the other parts to the gas storage vessel comprising a conduit, a cell connected to the gas storage vessel and having a palladium wall through which hydrogen diffuses to the ambient atmosphere, and said conduit being inclined upwardly throughout its length in the upright operating position of the apparatus and having angularly related sections projecting above the liquid level of solution in any tipped position of the apparatus.

2. In a vacuum type absorption refrigeration apparatus in which hydrogen is'apt to occur which interferes with its proper operation, means for circulating absorption solution in the apparatus, a gas storage vessel located above the highest level to which solution rises during operation of the apparatus, a conduit connecting the remainder of the apparatus to the gas storage vessel, means for transferring hydrogen through the conduit to the gas storage vessel, a cell connected to the gas storage vessel and having a palladium wall through which hydrogen ditfuses to the ambient atmosphere, and said conduit being inclined upwardly throughout its length in the upright operating position of the apparatus and having angularly related sections projecting above the liquid level or solution in any tipped position of the apparatus.

3. In a vacuum type absorption refrigeration apparatus containing absorption solution and in which hydrogen is apt to occur, means for circulating absorption solution in the apparatus, a gas storage vessel located above the highest level to which solution rises during operation of the apparatus, means for transferring hydrogen from the other parts of the system to the gas storage vessel comprising an auxiliary absorber, a fall tube pump, a separating chamber and a conduit extending upwardly from the separating chamber to the gas storage vessel, a cell connected to the gas storage vessel and having a palladium wall through which hydrogen diffuses to the ambient atmosphere, and said conduit connecting the separating chamber and gas storage vessel being inclined upwardly throughout its length and having angularly related sections projecting above the solution level at any tipped position of the apparatus.

4. In a closed absorption refrigeration apparatus containing absorption solution and in which hydrogen is apt to occur, a gas storage vessel located above the highest level to which solution rises during operation of the up paratus, means for transferring hydrogen from the other parts of the apparatus to the storage vessel comprising a conduit through which hydrogen flows upwardly, a cell opening into the center of the storage vessel and having a palladium wall through which hydrogen diffuses to the ambient atmosphere, said conduit being inclined upwardly throughout its length and having angularly related sections projecting above the solution level at any tipped position of the apparatus, and said storage vessel having suificient capacity below the cell opening at the center of the storage vessel to receive the amount of solution in the conduit when the apparatus istipped in any direction to an inverted position.

5. In an hermetically sealed vacuum type absorption refrigeration apparatus containing absorption solution and in which hydrogen is apt to occur, means for circulating solution in the apparatus, a gas storage vessel located above the highest level to which solution rises during operation of the-apparatus, means for transferring hydrogen from the other parts to the gas storage vessel comprising an upwardly directed conduit, a tube extending through the wall of the storage vessel having an open end positioned at the center of the vessel and a closed cell chamber at its opposite end, an upright palladium tube extending through the cell chamber and through which hydrogen diffuses to the ambient atmosphere, said conduit being inclined upwardly throughout its length and having angularly related sections projecting above the solution level at any tipped position of the apparatus, and said storage vessel having sufiicient capacity below the open end of the tube in any position to receive the amount of solution in the conduit when the apparatus is tipped to inverted position.

6. In a closed absorption refrigeration apparatus containing absorption solution and in which hydrogen is apt to occur, a purging device opening into said apparatus in a gas space above the surface level of absorption solution, said purging device having a palladium wall, and said gas space having sufficient volume below the purging device opening to hold the amount of solution entering said gas space when the apparatus is tipped into any position.

7. In a closed absorption refrigeration apparatus containing absorption solution and in which hydrogen is apt to occur, a gas storage vessel, means for transferring hydrogen from the other parts of the apparatus to said gas storage vessel, 2. purging device opening into the interior of said gas storage vessel and having a palladium wall through which hydrogen diffuses to the ambient atmosphere, said gas storage vessel having sufficient capacity below the purging device opening in the interior of the storage vessel to receive the amount of solution in said hydrogen transferring means when the apparatus is tipped in any direction to an inverted position.

References Cited in the file of this patent UNlTED STATES PATENTS 1,174,631 Snelling Mar. 7, 1916 2,320,349 Cropper June 1, 1943 2,374,564 Reid Apr. 24, 1945 

